All locking devices are subject to tampering, possibly resulting from loss of keys, duplication of keys, picking etc. Furthermore, in many instances, if visible signs of tampering do not exist, the fact that tampering has occurred may go unnoticed indefinitely. For example, utility meters are normally readable without access to the interior of the meter case so that, if tampering with the meter is unnoticeable, the fact that the meter case has been opened may go undiscovered. This is particularly true when barrel locks of the type conventionally used on meter boxes are improperly opened to expose the meter to tampering. At present, tamper protection for barrel locks involves periodically replacing the barrel lock mechanism, a solution which is both expensive and ineffective. Barrel locks, and other locks exposed to the environment, can become contaminated and problems with the proper functioning of the lock can occur, resulting in the need for the lock to be replaced. Similar problems can occur with respect to cash bags, mail pouches, computer cabinets, cable TV hookups and other secured enclosures that are situated in locations that are accessible to unauthorized persons. Thus, there is a need for a device which will not only provide a tamper deterrent seal for secured enclosures, but will also provide visible evidence of tampering. Secondarily, for lock arrangements that are exposed to the weather, a need exists for such a tamper deterrent seal that will, additionally, provide some weather protection for the lock mechanism.
Skarzynski et al U.S. Pat. No. 4,107,959 discloses a meter box guard lock wherein the box is locked through the use of a conventional barrel lock which is inserted into its locking position through a locking tube. In order to protect the lock from dirt and the weather, a plastic plug is inserted into the top end of the locking tube after the barrel lock has been secured in place. Furthermore, in order to deter tampering and efforts to pick the barrel lock, a conventional wire seal is threaded through a pair of diametrically opposed slots in the upper end of the locking tube and through a corresponding slot formed in the plastic plug. While this seal arrangement achieves some weatherproofing of the barrel lock, such an arrangement actually contributes to the possibility that tampering may be hidden. The wire seal can be shifted so as to enable the wire to be cut, and then the cut portion can be hidden within the slot of the plastic plug after tampering has been carried out and the meter box relocked and resealed.
In the Canney U.S. Pat. No. 4,416,478, a tamper deterrent seal providing an indication of tampering for watt hour meters is disclosed that provides a visual indication when an unauthorized attempt has been made to access the meter. That is, tampering will be visible because of the fact that the seal is constructed of a frangible material and has a head that is designed to readily fragment when placed under stress. While such a seal will provide adequate evidence of tampering, the construction disclosed by Canney requires that the meter box be specifically constructed for use with the tamper deterrent seal of that patent. Moreover, since this tamper deterrent seal of the Canney patent is a seal between housing components of the meter box, and not a seal disposed over the meter lock, itself, it can serve no weatherproofing function for the lock.
Although various other forms of protection for utility meters, such as padlock seals, lead and wire seals, dust caps, etc. exist on the market, all are either easily compromised and leave less than adequate evidence of tampering, require a special construction for the meter box itself and/or fail to provide weatherproofing for the lock. For example, Lundeberg U.S. Pat. No. 4,049,313 shows a plastic strip which extends through opposed slots in the collar of a barrel lock receiving bushing for a meter box. This strip fails to completely close the space within the collar.
In another environment, Anderson U.S. Pat. Nos. 4,112,990 and 4,008,914, as well as Moolenaars U.S. Pat. No. 4,062,090, all show reusable pouches having a zipper type closure and a sealing device for maintaining the zipper closed by holding the pull tab of the zipper in the position in which the zipper is closed. The seals of these patents include two parts, and expendable part and a reusable part mounted on the pouch. The expendable part is a button-like closure part that is engageable with the pouch-mounted reusable part and may only be removed from sealing engagement therewith by being broken, deformed or otherwise damaged so as not to be reusable. However, such pouch sealing arrangements require that the pouch be specifically manufactured with the reusable part of the seal as a part thereof, and this reusable part must have a complicated shape that is relatively costly to mold. Still further, since the portion of the button-like expendable part is hidden from normal inspection, it is possible to resecure a damaged button-like part (with something as simple as chewing gum) so that the fact that tampering has occurred will not be noticed until the pouch is re-opened. Alternatively, there is also the possibility that another, like, expendable button-like part might be utilized to reseal the pouch, if the tampering party has access to the same, since there is no means of determining that such a substitution has been made.
The latter-mentioned deficiency is overcome in the security seal and sealing system of Neto U.S. Pat. No. 4,106,801 by virtue of the fact that the breakable locking strip thereof is provided with an individual identification number. However, the locking strip of this patent requires that each of the two parts that are being secured together have one of a complex, molded cap and spool part attached thereto, thereby placing inherent limitations on the versatility thereof and significantly increasing the cost associated with use of the sealing system of that patent.
Lastly, padlock type seals, like conventional lead and wire type seals, are well known, and patents such as Foote U.S. Pat. No. 327,783 and Moore U.S. Pat. No. 2,003,753 show examples thereof. The seals of these patents use an elongated metal strip as a shackle, the ends of which are secured within a housing, after having been installed, and are designed such that it is impossible to remove the shackle ends from the housing without mutilation sufficient to indicate that the seal has been tampered with. However, the housinq of the Foote patent is expensive to produce because it is formed of metal that must be cast about a pin that is used for securing the two ends of the shackle. Furthermore, fastening of the pin requires use of a punch or press to force the pin into the metal wall forming an opposite side of a slot for receiving the shackle ends. Similarly, even though the Moore patent does not require a punch or press for securement purposes, this seal is also expensive to produce due to the multipartite construction of the housing and the need to incorporate a rotatable member therein that is used to deform an end of the shackle strip after it has been inserted into the housing.
Thus, there is a need for a seal that can be serial numbered, leaves evidence of tampering, cannot be glued or replaced easily, is simple in construction and easy to install, while being universal in application and cost-effective. Furthermore, for outside applications, a seal that possesses the preceding characteristics and also affords weather protection for the lock is also desirable.